Penetration of ofloxacin in human aqueous and vitreous humors following oral and topical administration

Purpose: To determine aqueous and vitreous humor ofloxacin levels following oral and topical application of ofloxacin in patients with noninflamed cor nea and intact crystalline lens, and to compare the drug levels provided by each route. Materials and Methods: Twenty-six patients undergoing pars plana vitrectomy for various ocular pathologies were divided into two groups. Fourteen pati ents received two drops of 0.3% ophthalmic solution of ofloxacin every 30 m inutes for 3 hours and every 60 minutes for the next 3 hours, and 12 patien ts received a single oral dose of 400 mg ofloxacin 8 hours before surgery. The aqueous and vitreous humor samples were simultaneously collected after oral or topical administration during pars plana vitrectomy to assess penet ration of the drug. Samples were assayed for ofloxacin concentrations by a previously described method using high-performance liquid chromatography. Results: The aqueous and vitreous humor levels of ofloxacin were 1.54 +/- 0 .27 mu g/mL (mean +/- standard error) and 1.77 +/- 0.24 mu g/mL after oral and 1.44 +/- 0.24 mu g/mL and 0.37 +/- 0.05 mu g/mL after topical ofloxacin administration, respectively. Aqueous humor levels were not statistically different following oral or topical administration (P > 0.8). However, vitr eous level of the drug after oral administration was significantly higher t han that after topical administration (P < 0.001). Conclusion: Ocular bioavailability of ofloxacin in aqueous humor after oral and topical administration is similar when the drug is applied as describe d. Penetration of ofloxacin into vitreous humor is less than that into aque ous humor following topical application. The aqueous humor levels of ofloxa cin via both routes and the Vitreous level of the drug after oral route exc eed the minimum inhibitory concentrations for certain bacterial species tha t frequently cause intraocular infection.